Biotechnological Journal of Environmental Microorganisms
Year:2012 | Volume:6 | Issue:3 (3)|Papers Count:8

The Caspian sea in the coastal province of Guilan in the central and western regions have further contamination rather than eastern regions that could be due to the expansion of industry and industrial waste water and household discharges within rivers and Caspian sea. Also, the presence of Anzali lagoon, Astara Lavandavil, wastewater discharges, agricultural drainage waters and types of household wastes and others is considered as contaminating agents at coastal waters in these regions. The purpose of this study is evaluation of microbial contamination in western rim of rivers at Caspian Sea from Port-of-Astara to Port-of-Anzali. In this descriptive survey, three coastal stations at Caspian sea in Guilan province identified and then these locations have been studied from view of microbial pollution by microbial indices including coliforms and hot waters associated with pH, temperature and turbidity during summer season by standard method in 2012. The obtained data were analyzed by using statistical software. The results of the study showed that the rivers were contaminated by allochtonic organic matters and environmental wastes. Also, presence of enterobacter species is indicator of contaminated rivers with human feces. According to the findings, one of the most important causes of microbial contamination of sea water and coastal plan is the rivers that in its own path with collecting of effluent and urban, rural, agricultural, industrial and surface drainage waters and rainfall are pollutated and subsequently, cause pollution of coastal waters and beaches.

Actinomycetes are gram positive bacteria with high GC percent of 57—75%. Actinomycetes were initially considered an intermediate group between bacteria and fungi, but are recognized as prokaryotic now.The aim of this study was isolation, screening and determination of anti-bacterial properties isolates against standard strains including Salmonella typhi PTCC: 1609, Staphylococcus aureus PTCC: 1113, Klebsiella pneumoniae PTCC: 1402, Bacillus subtilis PTCC: 1365 and also investigating relationship between soil moisture and pH with distribution of these bacteria. In this study, we used for isolation of actinomycetes, Starch Casein Agar (SCA) medium and for primary screening, spot inoculation method. Then in submerge method for production of antibiotic, International streptomyces project 2 (ISP2) medium was used.Then, well diffusion method to final screening and antibiotic susceptibility test were applied. In this study, 30 soil samples collected from different parts of Golestan forest and isolated 50 strains of actinomycete from these soils. Then by using spot inoculation method, 15 (30%) isolates of actinomycetes showed good antibacterial activity against tested bacteria and 35 (70%) isolates had not antibacterial activity. Then by using submerge culture method in ISP2 broth and by final screening of isolates by method of well diffusion, 5 (10%) isolates including Gs17, Gs19, Gs21, Gs23 and Gs25 showed best antibacterial activity against the tested bacteria, respectively. In well diffusion method 6% of isolates showed antibacterial activity against gram positive bacteria and also total gram-positive and gram-negative bacteria and 10% of isolates showed antibacterial activity against gram-negative bacteria. We also found a significant relationship between soil moisture and pH with isolation frequency.

Xylitol is a natural five-carbon alcoholic sugar that has been highly valued by the food and pharmaceutical industries because of its sweetening power (as high as sucrose), potential uses as dental caries reducer and as insulinin dependent carbohydrate source for insulin-dependent diabetics. The purpose of this study was optimization of medium components and culture conditions in order to increase xylitol production by Pichia guilliermondii. Firstly, the effects of carbon, nitrogen and culture conditions were optimized by one-factor-at-a-time method, then nutritional improvement was performed using Taguchi method as a fractional factorial design in two stages. The selected carbon sources were Xylose, Fructose, Rafinose, Lactose, Manitol, Galactose, Maltose, Sucrose and Glucose. The complex and inorganic substrates were Whey, Sodium nitrate, Sodium nitrite, Potassium nitrate, Yeast extract and Pepton, respectively. The results showed that amongst different carbon sources, Xylose had significant effect on xylitol production and amongst variety of nitrogen sources, Yeast extract and Peptone were the most suitable sources, respectively. The optimum temperature, inoculum size and pH were 30oC, 7% (V/V) and 7, respectively. Xylitol production was 51.25% in the basal medium. It was concluded that by optimizing using one-factor-at-a-time and Taguchi methods, led to increase in xylitol production to 68% and 89%, respectively.

Caspian Sea is one of the most valuable ecosystems in the world and contain a high diversity of fungal species with capable of producing the enzyme. Lipases (triacylglycerol acyl hydrolases, EC 3.1.1.3) catalyze the hydrolysis and the synthesis of esters formed from glycerol and long-chain fatty acids. Lipases occur widely in nature, but only microbial lipases are commercially significant.Microbial lipases are currently receiving much attention with the rapid development of enzyme technology. The aim of this study was isolation and identification of lipase-producing fungi from the coastal waters of the Caspian Sea. In this study, 25 fungal species were isolated from southern coasts of the Caspian Sea in spring 2011 and tested to determine their lipolytic activity by screening techniques on tributyrin agar media. Four lipase-producing fungi were selected and their PCR identification and sequencing were carried out. Determination of the nucleotide sequencing of the ITS-5.8S rDNA gene showed that these isolated species belonged to genera Cladosporium, Glomerella and Phaeosphaeria. Among them, two species of Glomerella acutata and Cladosporium cladosporioides showed higher lipase activity.

The excessive use of antibiotics for disease treatment were increased antibiotic resistance among microorganisms and in the other hand the side effects will be appeared in patients considering, the need to develop new antimicrobial therapies, in recent years much attention has been paid to the use of natural resources, especially medicinal plants. One of these medicinal plant used in traditional medicine in Iran and the world, is Ruta graveolense that, it has significant therapeutic effects and contain many antibacterial and antifungal substances. The aim of this study is evaluation antimicrobial effects of aqueous and alcoholic extracts of this plant on Gram positive and negative Bacteria using agar diffusion method (disk and well) on bacteria Staphylococcus aureus PTCC 1431, Bacillus subtilis PTCC 1720, E. coli PTCC 1763, Pseudomonas aeruginosa PTCC 1599. The results showed using aqueous, methanolic and ethanolic extracts had effects in disk and well method on Staphylococcus aureus PTCC 1431, Bacillus subtilis PTCC 1720 with different MBC and MIC. But only the aqueous extract on E. coli PTCC 1763 and methanolic and aqueous extracts effective on Pseudomonas aeruginosa PTCC 1599 with different MBC and MIC.

In most studies related to plants transformation, the antibiotic resistance genes are used for recovery of transgenic plants, but introducing such products into the food chain may lead to biosafety concerns. In this study, Betaine Aldehyde Dehydrogenase (BADH) gene was used as non-antibiotic marker in designing of Plastid vector. The gene sequences from spinach after introns removal decreased from 6111bp to 1494bp, then the codon optimization was performed based on common codon used in the Plastid Genome and eight of internal restriction enzyme recognition sites in coding region were also removed by changing the nucleotide sequences without changing the amino acids. Increasing of TA percent was also considered in this codon optimization. The final sequence of BADH gene was connected to 5' UTR of T7gene10 and placed under strong Prrn chloroplast promoter by SOEing PCR. RBS and MCS were inserted between promoter and BADH. By cloning of desired genes in this position, expression of them will be polycistronic with BADH and not only Plastid transformation will be possible without antibiotic selective marker, but also we would expect transgenic plants that express BADH, to be resistant to salt, drought and cold stresses.

The heavy metal pollution has become one of the most important environmental problems. Heavy metals are the most important environmental pollutants, especially for human health and aquatic systems are a serious threat. Iranian Research Organization for Science and Technology of yeast Saccharomyces carlsbergensis PTCC 5051, and received as a lyophilized culture YEDPA environment and then the proliferation of malt extract broth is used. The effects of pH, temperature, kinetics and isotherm of lead on metal uptake were evaluated by the SC. Absorption maximum at about pH 5, the optimum temperature was 25 degrees Celsius. A kinetic study showed that batch biosorption of lead to rapid removal by the biomass of Saccharomyces was the first test was done in less than 30 minutes. Using FT-IR Method, surface functional groups of fungi were identified. With active and passive absorption of lead by Saccharomyces, It has revealed that most absorption takes place by active yeast. With yeast and control yeast on the autoclave, the pre-treated with sodium azide and 2, 4 Dinitrophenol (DNP) showed that claims of capturing, respectively, 0.68, 0.12, 0.44 and 0.48 Mmol gram was obtained. Results showed that, even using the passive yeast are suitable for the Bioabsorption of lead.

Biosurfactants are surface active substances produced by a variety of bacteria, yeast and fungi. Adhesion molecules in both aqueous solutions and hydrocarbon mixtures are reduced. The aim of this study was the isolation and identification of Biosurfactants-producing bacteria that can use the process of enhanced oil recovery and oil degradation has. In this study, all samples of oil, water and soil contaminated with petroleum from oil reservoirs in emulsion of Kermanshah on oil degrading bacteria were cultured in appropriate medium. Hemolytic activity, activity emulsion action and surface tension measurements, respectively, were used as the initial screening and isolation of Biosurfactants production. Selected strains were identified by biochemical tests. Also, the ability to analyze the nature and effect of crude Biosurfactants strains selected for analysis. Only twenty-four of the 88 strains isolated bacterial strains were hemolytic activity among 12 strains produced over 70 percent of emulsion activities. At the end of these four strains 43, 47, 83 and 88 were able to reach the surface tension of less than mN/m40.In this study, based on biochemical tests, anaerobic gram-positive and were identified as Bacillus pumillis 47. Results from the nature of the biosurfactant was determined by thin-layer chromatography was lipopeptide type. Biosurfactants producing strains also have selective antibacterial activity against six infectious bacteria, Staphylococcus aureus 1112 PTCC, Escherichia coli 1330 PTCC, Pseudomonas aeruginosa1074 PTCC, Staphylococcus epidermidis 2405 ATCC, 2601 ATCC Proteus mirabilis and Salmonella typhimurium 1679 ATCC. Evaluation of growth inhibition zone diameter of biosurfactant dilution effect on any bacteria and then bacteria compared with that of the most sensitive bacterium Bacillus pumillis biosurfactant extract, Staphylococcus epidermidis is the most resistant Salmonella typhimurium. Results MIC, MBC, showed that MIC of the extract at 63 mg ml had the greatest impact on bacteria Staphylococcus epidermidis, and concentration MBC at 125 mg ml extract on Staphylococcus aureus, Staphylococcus epidermidis was the most effective. Thus, according to these results, we can say that these bacteria have great potential for applications in biotechnology and environmental requirements. Thus, using a combination of anti-bacterial products Biosurfactants pause.